David had made peace with the remnants of Saul’s army and had taken steps to unite the nation after their civil war. Yet, David’s General, Joab, could not abide Saul’s former general, Abner, becoming part of David’s army. There were probably several reasons but most of all because Abner had killed his brother, Ahazel, in the battle at Gibeon.
To take his revenge, Joab used deceit to trap and kill Abner. David, the man after God’s heart, had refused to take revenge against his enemy, Saul, on many occasions. It was because of his patience in letting God judge his enemies that David had received God’s many blessings on his reign. In response to Joab taking his own vengeance, David pronounced curses on him. Verse 29 of 2 Samuel chapter 2 says, “May it fall upon the head of Joab and upon all his father’s house, and may the house of Joab never be without one who has a discharge or who is leprous or who holds a spindle or who falls by the sword or who lacks bread!” The curses involved sickness, poverty and failure.
According to the Minirth and Meier book “How To Beat Burnout,” people who are bent on resentment & revenge make themselves sick. They become less effective in life (failure) and often lose opportunities for advancement and sometimes employment (poverty). They argue that in their years of counseling resentment, bitterness and desire for revenge is closely connected with burnout. Sleep disorders are often associated with resentment and bitterness and grudge carrying as well.
I expect the same curses fall on those bent on revenge today as well. Besides Jesus taught us “Whenever you stand up to pray, forgive whatever you have against anyone, so that your Father in heaven will forgive your sins. But if you do not forgive, your Father in heaven will not forgive your sins.” (Mark 11:25:26)